Saturday, October 29, 2016

Apache
Felix is one of the implementation for OSGi framework. We
can download implementation and it will provides the OSGi container to provide
runtime environment for OSGi bundles. We can develop bundles and install, start
in Apache Felix OSGi container.
These bundles should follow the OSGi specification then only it can be deployed
into OSGi container such as the implementation provided by Apache Felix.

Liferay 7 have used Apache Felix implementation to support modularity application
development while developing Liferay 7 Applications.

Another directory called felix-cache this will provide cache for bundles and its default directory
and we can change cache folder from properties file.

bundle

Bundle directory is auto deployment directory for
OSGi container. Bundles which are deployed in this directly automatically started
and running when OSGi container started.

Whenever the bundles are mandatory and that should
needed for our environment then we can place these OSGi bundles in bundle directory so that it will be
started and running automatically by OSGi container when it launched.

Apache Felix is providing the Command Line Interface (CLI) to manage or handle bundles and this implementation
called Apache GoGo Shell. These
bundles should start along with OSGi container that is why these bundles are
placed in bundle directory.

We have file called config.properties and it will contains all the required properties.
We have list of properties that can be available to configure and all are
listed in the document apache-felix-framework-configuration-properties
and it’s available in doc directory.

doc

Doc directory contains all documents about Apache
Felix and there are html pages you can directly open and read the documentations.

Start
Apache Felix

Open command prompt and navigate Apache Felix home directory
from there run the following command then Apache Felix will launch

java –jar bin/felix.jar

Once it started you can see Apache GoGo Shell command line interface from there we can manage
bundles life-cycle.

Note:

Apache
GoGo
already available in default deployment directory that is why when you launch Apache Felix then Apache GoGo bundles also started then it will be available for use.

Once Apache
Felix stated then you can see Apache
GoGo shell command as follows

Type help
command in the GoGo shell then we
can see list of commands available.

Type lb or
felix:lb command it list the
available bundles in the OSGi container and shows its states(Active, Installed,
DeActive)

Install
and Start OSGi bundles.

Once we developed the OSGi bundle by following the framework
specification then we can deploy these bundles into OSGi container.

We can start bundle and stop bundle using Apache GoGo shell command with commands.

First need to install bundle then start the bundle. We
can install bundle from any location by proving bundle path.

The following is the way to install, start and stop
bundles.

Install
Bundle

install file:/path/to/bundle/bundle.jar

OR

felix:install file:/path/to/bundle/bundle.jar

List
Bundles

lb

OR

felix:lb

Start
Bundle

start bundle-id-in-list

OR

felix:start bundle-id-in-list

Stop
Bundle

stop bundle-id-in-list

OR

felix:stop bundle-id-in-list

The following is screen to shows the bundle life-cycle

Note:

OSGi bundle is packaged jar file.

Apache Felix used default port 8080 for http service and to change this
port we have property in config.properties
file.